JAVA calculation of two latitude-longitude relationship calculation __java

Java calculates the distance between two GPs coordinate points

1. LAT1 Lung1 represents the latitude and longitude of a point, Lat2 Lung2 the latitude and longitude of B point;

2. The difference between the latitude of A=lat1–lat2 two points b=lung1-lung2 the difference of longitude of two points;

3.6378.137 is the earth radius, the unit is kilometer;

The calculated result unit is a kilometer.

The code from Google Maps's script is used to calculate the latitude and longitude between two points.

Private Const Double Earth_radius = 6378.137;
private static Double rad (double D)
{
    return d * math.pi/180.0;
}
public static double Getdistance (double lat1, double lng1, double lat2, double lng2)
{
    Double RADLAT1 = rad (LAT1);
    Double radLat2 = rad (LAT2);
    Double A = RADLAT1-RADLAT2;
    Double b = rad (lng1)-Rad (LNG2);
    
     Math.Cos (RADLAT1) *math.cos (RADLAT2) *math.pow (Math.sin (B/2), 2));
    s = S * earth_radius;
    s = Math.Round (S * 10000)/10000;
    return s;
}

The following code can be used in Android to get the distance

Public double getdistance (double lat1, double lon1, double lat2, double lon2) {
    Float[] Results=new float[1];
    Location.distancebetween (LAT1, Lon1, LAT2, Lon2, results);
    return results[0];
}

In other devices if there is no Android-like location of the Distancebetween method to use the following code to obtain

The result of this calculation is a mile, and if you want to convert it to a kilometer, multiply by 1.609344 if you need to multiply it by 0.8684.

Double distance (double lat1, double lon1, double lat2, double lon2) {
    Double theta = Lon1-lon2;
    Double dist = Math.sin (Deg2rad (LAT1)) * Math.sin (Deg2rad (LAT2))
                + Math.Cos (Deg2rad (LAT1)) * Math.Cos (Deg2rad (LAT2))
                * Math.Cos (Deg2rad (theta));
    Dist = Math.acos (dist);
    Dist = rad2deg (dist);
    Double miles = Dist * 60 * 1.1515;
    return miles;
}

//Convert angle to radians 
 static double Deg2rad (double degree) {
 return degree/180 * MATH.PI; 
}